Lord MicroStrain G-Link-200 User manual

G-Link®-200
Wireless Accelerometer Node
LORD
USER MANUAL

LORD Sensing Systems 459 Hurricane Lane
Williston, VT 05495 United States of America
Phone: [phone]
Fax: [phone]
http://www.microstrain.com
[email protected]
[email protected]
Document 8500-0069 Revision K
Subject to change without notice

Table of Contents
1.0 Wireless Sensor Network Overview .....................................................................................................1
2.0 Node Overview.....................................................................................................................................2
2.1 Components List................................................................................................................................3
2.2 Interface and Indicators .....................................................................................................................4
2.3 Node Operational Modes ..................................................................................................................5
2.4 System Operation..............................................................................................................................6
3.0 Software Installation..............................................................................................................................7
3.1 Gateway USB Communication ..........................................................................................................8
3.2 Connect to Nodes..............................................................................................................................9
3.2.1 Add A Node Via Node Discovery ................................................................................................9
3.2.2 Add A Node Manually ...............................................................................................................10
3.2.3 Move Node To Base Station Frequency ...................................................................................12
4.0 Wireless Sensor Configuration............................................................................................................13
4.1 Hardware Configuration...................................................................................................................13
4.2 Calibration Configuration .................................................................................................................14
4.3 Sampling Configuration ...................................................................................................................15
4.4 Power ..............................................................................................................................................17
5.0 Wireless Sensor Sampling Configuration .........................................................................................18
5.1 Start Collecting Data .......................................................................................................................18
5.2 Network Options..............................................................................................................................19
5.2.1 Synchronized Enabled .............................................................................................................19
5.2.2 Synchronized Disabled ............................................................................................................20
5.2.3 Lossless Enabled.....................................................................................................................20
5.2.4 Lossless Disabled ....................................................................................................................20
5.3 Raw Waveform Channels................................................................................................................21
5.4 Derived Output Channels ................................................................................................................22
5.4.1 Windows ...................................................................................................................................23
5.4.2 Chunks......................................................................................................................................24
5.4.3 Under-sampling ........................................................................................................................25
5.4.4 Incoherence ..............................................................................................................................25
5.5 Sampling Operations Options..........................................................................................................25
5.6 Data Type ........................................................................................................................................27
5.7 Output Operation.............................................................................................................................28
6.0 Viewing Data ......................................................................................................................................29
6.1 SensorCloud....................................................................................................................................29
6.1.1 Connect to SensorCloud...........................................................................................................29

6.1.2 Navigating Menus .....................................................................................................................30
6.2 SensorConnect................................................................................................................................32
6.2.1 Using Dashboards and Widgets................................................................................................32
6.2.2 Navigating Graphs ....................................................................................................................33
6.2.3 Widgets Options .......................................................................................................................33
6.2.4 Time Series Widget Menu ........................................................................................................34
6.2.5 Exporting Data Files..................................................................................................................34
7.0 Installation...........................................................................................................................................35
7.1 Mounting Recommendations...........................................................................................................35
7.2 Optimizing the Radio Link................................................................................................................36
7.2.1 Range Test ...............................................................................................................................37
8.0 Troubleshooting ..................................................................................................................................38
8.1 Troubleshooting Guide ....................................................................................................................38
8.2 Updating Node Firmware.................................................................................................................41
8.3 Repair and Calibration.....................................................................................................................42
8.3.1 General Instructions..................................................................................................................42
8.3.2 Warranty Repairs ......................................................................................................................42
8.3.3 Non-Warranty Repairs ..............................................................................................................42
9.0 Parts and Configurations ...................................................................................................................43
9.1 Node Accessories............................................................................................................................43
9.2 Wireless System Equipment ...........................................................................................................43
10.0 Specifications....................................................................................................................................44
10.1 Physical Specifications..................................................................................................................44
10.2 Operating Specifications................................................................................................................45
10.3 Mechanical Shock Limits ...............................................................................................................46
10.4 ASTM F2137-19 Compliance: G-Link-200-R.................................................................................47
10.4.1 Overview.................................................................................................................................47
10.4.2 Specification ...........................................................................................................................47
10.4.3 Setup ......................................................................................................................................48
10.4.4 Calibration...............................................................................................................................49
11.0 Safety Information............................................................................................................................50
11.1 Powering the Node ........................................................................................................................50
11.2 Replacing Batteries .......................................................................................................................50
11.3 Battery Hazards.............................................................................................................................51
11.4 Disposal and Recycling .................................................................................................................51
11.5 Radio Specifications......................................................................................................................52
11.6 Frequency Setting .........................................................................................................................52
12.0 References........................................................................................................................................53

12.1 Technical Support..........................................................................................................................53
12.2 Product Ordering ...........................................................................................................................53
12.3 Related Documents .......................................................................................................................54

1
1.0 Wireless Sensor Network Overview
The LORD Sensing Wireless Sensor Network is a high-speed, scalable, sensor data
acquisition and sensor networking system. Each system consists of wireless sensor
interface nodes, a data collection gateway, and full-featured user software platforms
based on the LORD Sensing Lossless Extended Range Synchronized (LXRS) data
communications protocol. Bi-directional wireless communication between the node and
gateway enables sensor data collection and configuration. Gateways can be connected
locally to a host computer or remotely via local and mobile networks. Some gateways also
feature analog outputs for porting sensor data directly to stand-alone data acquisition
equipment.
The selection of available nodes allows interface with many types of sensors, including
accelerometers, strain gauges, pressure transducers, load cells, torque and vibration
sensors, magnetometers, 4 to 20mA sensors, thermocouples, RTD sensors, soil moisture
and humidity sensors, inclinometers, and orientation and displacement sensors. Some
nodes come with integrated sensing devices such as accelerometers. System sampling
capabilities include lossless synchronized sampling, continuous and periodic burst
sampling, and data logging. A single gateway can coordinate many nodes of any type,
and multiple gateways can be managed from one computer with the SensorConnect and
SensorCloud software platforms. Integration to customer systems can be accomplished
using OEM versions of the sensor nodes and leveraging the LORD Sensing data
communications protocol.
Common wireless applications of LORD Sensing Sensing Systems are strain sensor
measurement, accelerometer platforms, vibration monitoring, energy monitoring,
environmental monitoring, and temperature monitoring.

2
2.0 Node Overview
The G-Link-200 wireless accelerometer node features an onboard triaxial accelerometer
that allows high resolution data acquisition at noise levels as low as 25 or 80 µg√ Hz. The
G-Link-200 can output continuous waveform data, or one of four derived channels,
including Velocity (IPSrms), Amplitude (Grms and G pk- pk) and Crest Factor, allowing long-
term monitoring of key performance indicators while maximizing battery life.
G-Link-200 inputs are 20-bit resolution with ± 0.1% full scale measurement accuracy. The
node can log data to internal memory, transmit real-time synchronized data, and it
supports event driven triggers with both pre- and post- event buffers.
To acquire sensor data, the G-Link-200 is used with a LORD Sensing data gateway such
as the WSDA-200 USB or WSDA-2000.
Figure 1 - G-Link-200

3
2.1 Components List
G-Link-200 sensor nodes come with the following components and options. For a
complete list of available configurations, accessories, additional system products and
ordering information, see 9.0 Parts and Configurations.
Item
Description
Quantity
A
G-Link-200 1
B
½ AA, 3.6 V Lithium Batteries 3
--
Calibration Certificate
1

4
2.2 Interface and Indicators
The G-Link-200 LEDs indicate operational modes showing when the node is booting up,
idle and waiting for a command, sampling, resynchronizing, or if there is an error.
Indicator
Behavior
Node Status
Device
status
indicator
OFF
Node is OFF
Rapid green flashing
on start-up Node is booting up
1 (slow) green pulse
per second
Node is idle and waiting
for a command
1 green blink every 2
seconds Node is sampling
Blue LED during
sampling Node is resynchronizing
Red LED
Error or low battery
Table 1 - Indicator Behaviors

5
2.3 Node Operational Modes
Sensor nodes have three operational modes: active, sleep, and idle. When the node is
sampling, it is in active mode. When sampling stops, the node is switched into idle mode,
which is used for configuring node settings, and allows toggling between sampling and
sleeping modes. The node will automatically enter ultra low-power sleep mode after a
user-determined period of inactivity. The node will not enter sleep mode while sampling.
Figure 2 - Node Operational Modes

6
2.4 System Operation
The gateway is the interface between LORD Sensing sensor nodes and the data
acquisition computer. The gateway coordinates the configuration and sampling of the
nodes and can handle many nodes simultaneously. Communication between the nodes
and gateway is wireless and uses the LORD Sensing LXRS and LXRS+ data
communications protocols.
LORD Sensing has two software programs available for data acquisition from the wireless
sensor network: SensorCloud and SensorConnect. SensorCloud is an optional web-
based data collection, visualization, analysis, and remote management platform, based on
cloud computing. SensorConnect is PC-based software used for configuring gateways
and nodes, selecting and sampling modes and parameters, initializing data acquisition, and
viewing and saving data.

7
3.0 Software Installation
Install the SensorConnect software on the host computer before connecting any hardware.
Access the free software download on the LORD Sensing website at:
http://www.microstrain.com/software
NOTE
The SensorConnect software includes hardware drivers required for use with USB
gateways. Once installed, the software will automatically detect and configure any USB
gateways that are plugged into the host computer.
SensorCloud is an optional data collection, visualization, analysis, and remote
management tool. It is based on cloud computing technology and is accessed directly
from a web connection. For more information go to: http://www.sensorcloud.com/.

8
3.1 Gateway USB Communication
Drivers for the USB gateways are included the SensorConnect software installation. With
the software installed, the USB gateway will be detected automatically whenever the
gateway is plugged in.
1. Power is applied to the gateway through the USB connection. Verify the
gateway status indicator is illuminated, showing the gateway is connected
and powered on.
2. Open the SensorConnectsoftware.
3. The gateway should appear in the Controller window automatically with a
communication port assignment. If the gateway is not automatically
discovered, verify the port is active on the host computer, and then remove
and re-insert the USB connector.
Figure 3 - USB Gateway Communication

9
3.2 Connect to Nodes
Several methods can be used in SensorConnect to establish communication with the
nodes: the automatic node discovery feature, manually entering the node address, and
scanning transmission frequency and node address ranges.
3.2.1 Add A Node Via Node Discovery
If the base and node are on the same operating frequency, the node will populate below
the Base Station listing when powering on the G-Link-200.
Figure 4 - Node Discovered On Same Frequency
If a red circle with a number appears next to the Base Station, the node is operating on a
separate radio channel.
Figure 5 - Node On Other Frequency

10
3.2.2 Add A Node Manually
Adding a node manually requires entering the node address and its current frequency
setting.
From the Base Station, select the Manual Add Node tile, enter the Node Address, last
known Frequency (factory default is 15), and select Add Node.
Figure 6 - Add Node By Address
If the node was successfully added, two confirmation messages appear and it will be
listed under the Base Station.
Figure 7 - Add Node Confirmation

11
If the node failed to be added, a failure message will appear. This means the node did not
respond to the base station which could indicate the node is not in idle mode or it may be
on another frequency. If "Add Node Anyway" is selected, it will associate that node with
the channel entered but it is likely there will be a communication error. If the node was not in
idle, move the base station to the frequency of the node and issue a "Set to Idle" command.
Figure 8 - Failure to Add Node

12
3.2.3 Move Node To Base Station Frequency
If a red circle with a number appears next to Base Station, the node is operating on a
separate radio channel. Select the Base Station and then select the Nodes on Other
Frequencies tile.
Figure 9 - Nodes On Other Frequencies
Highlight the new node being added and select Move Node to Frequency (#).
Figure 10 - Move Node

13
4.0 Wireless Sensor Configuration
4.1 Hardware Configuration
Node settings are stored to non-volatile memory and may be configured using
SensorConnect. This chapter describes the user-configurable settings.
Figure 11 - Node Configuration Menu
Input Range - Set the accelerometer range to fit the application. Available ranges
are
±2.048 g, ±4.096 g, and ±8.192 g.
Low Pass Filter and Group Delay - The accelerometer provides two filter stages for
limiting bandwidth and maintaining excellent noise performance. The first stage is an
analog, fixed frequency, anti-aliasing filter with -3 dB attenuation at 800 Hz, and 6.18 dB
attenuation at 1500 Hz. The second is a user adjustable digital decimation filter. The
decimation filter allows low-pass filtering between 26 Hz to 800 Hz on each channel
independently. To minimize aliasing, it is recommended that users set the low pass filter to
a frequency ¼ that of the sample rate or less.
Group Delay is the time delay of the signal amplitude imparted by the low pass filter.
Table 2 displays group delay values corresponding to the low pass filter configuration.
Low Pass Filter (Hz) at -3 dB
Group Delay (ms)
800
0.88
418
1.51
209
2.75
104
5.27
52
10.31
26
20.38
Table 2 - Group Delay
High Pass Filter - The accelerometer contains an optional high-pass filter which is
disabledbydefault. Thehigh-passfilter corner frequencyiseffectedbythelow passfilter

14
setting.Whenenabled,thehighpassfilter-3dBpointwillbeequaltothecorrespondinglow
pass filter value as shown in Table 2 below.
Low Pass Filter (Hz)
Resulting High Pass Filter
(Hz)
800
2.48
418
1.24
209
2.48
104
1.24
52
0.62
26
0.31
Table 3 - High Pass Filter Values
4.2 Calibration Configuration
Each node is calibrated at the factory and stores its linear calibration coefficients in
nonvolatile memory. These coefficients are applied by the node when the node is
outputting data in “floating point” format. The coefficients are applied automatically by
SensorConnect when the node is outputting data in signed 16- bit or signed 24- bit
formats. For the available data types, the calibration coefficients are applied as follows:
•
Float (4 Bytes): Calibration applied by node
•
Int24 (3 Bytes): G-force = value * slope + offset
•
Int16 (2 Bytes): G-force = 64 * value * slope + offset
Figure 12 - Wireless Sensor Calibration Menu

15
4.3 Sampling Configuration
There are three user set sampling options for the G-Link-200, including Lost Beacon
Timeout, Diagnostic Info Interval, and Storage Limit Mode, in the Wireless
Node Configuration > Sampling menu.
Figure 13 - Sampling Configuration Menu
Lost Beacon Timeout -Whenthenodeisrunninginasynchronizednetwork,it
periodically synchronizesitstimeclocktoabeaconbroadcastedfromtheWSDA
gateway.TheLost Beacon Timeout feature means that the node will automatically
stop sampling and transmitting dataafter thebeaconhasbeenlostfor theconfigured
amount oftime.The nodewillsavepowerinthisstatewithoutuserinterventionuntilthe
beaconreturns.Within two minutes of the beacon returning, the node will
automatically begin sampling and transmitting dataagain.
Diagnostic Info Interval -Atthedefinedtransmitinterval, the wirelesssensorwillreport
diagnostic information. The node will continue to transmit this diagnostic information in all
operating modes, including Idle, Sleep, and Run modes.
Storage Limit Mode - TheStorageLimitMode applieswhen thenodeisdataloggingto
internal flash. The two available options are: 1)
Stop - when the node fills up its flash
memory,itwillstoploggingdata. Itisimportanttoeraseolddatabeforestartingnew data
loggingsessions,and2)
Overwrite - whenthenodefillsupitsflashmemory,newdatawill
overwrite old data in a first-in, first-out method.